Text filled by balls
If no one ... classic


add Text convert to Mesh
add Balls, set in Collection, add Physics > Riggid Body > Active
add Particle system > Source from Volume, Render > Collection
enable addon Copy Particles to Riggid Bodies, run operator (take some time)
disable particle system for Text (Mesh) object and add Physics > Riggid Body > Passive


To change letters - type a new text, convert to mesh, assign Particle system, run addon, set Riggid Body. 

I know almost the same, but still just a few clicks now, that you would have to in C4D as well (if I checked tut right).

 

Note: Particles were quite jumping out (because I did them too big), so I did a duplication of Text mesh and inset the shape, so they are generated from object inside collision Text mesh.




Naming of the addon could be improved cross UI, but awesome it exists.